Variable-speed pulley



March zo, 192s. f y 1,663,414 A. H. M'lzE VARIABLE sPEEu PULLEY Fl'ed Sept. 10. 1926 4 Sheets-Sheet 1 INVENIOR ATroRNEYs March 20, 1928.

A. H. MIZE VARIABLE SPEED PULLEY Filed Sept. 10. 1926 4 Sheets-Sheet 2 lNvENToR Jler-Z Mz'ze ATTORNEYS WITNESSES A. H. MIZE VARIABLE SPEED PULLEY Filed Sept. 10. 1926 44 Sheets-Sheet 3 March 20, 1928. I 1,663,414

March 20, 1928. 1,663,414

' A. H. MlzE VARIABLE SPEED PULLEY Filed Sept. 10. 1926 4 Sheets-Sheet 4 d v INVENTOR wnNEssEs Y l .Hlerl E Maze l BY y il a 5&4.

ATTORNES Patented Mar. 20, 1928.

UNITED STATES 1,663,414 "PATENT OFFICE.

ALEERT HORACE iarzE, oF GREENVILLE, 'soUcr'H CARLINA.

VARIABLE-SPEED PULLEY.

y Application led September 10, 1926. Serial No.'134,727.'-

The present invention is concerned with -thc provisions of improvements invariable speed pulleys of the character employed for changing the speed ratio between a driving a shaft and a driven shaft where the drive 'is effected through the intermediacy of belts. The prime object of the present invention is to provide a pulley of this character so constructed that'there will be no parts of c the pulley in motion relative to each other except at the time that the diameter of the pulley is being changed.

, A further object of the invention is to provide 'an adjustable speed pulleywhich 5 includes a pair of pulleys formed of radially adjustable segments and so constructed that the contraction or reduction of diameter of one pulley automatically effects the eX- pansion of the other pulley. f ir Preferablythe pulley struct-ure is mount- "ed upon a pivoted hanger frame, one pulley being connectedby a belt to the drive shaft and the other pulley being connected by la beltpto lthe driven shaft. Means is provided for swinging the yframe thereby automatically tightening one beltabout its pulley Wand loosening theother belto'n its pulley.

The tightening of the belt in itself effects con-y traction of the pulley with which itis asso- Ociated and causes expansion of the other pulley to take up the slack in its belt.

Other and more general objects of the invention are to provide a variable speed pulley of simple, practical construction,

which will be rugged, durable and eicient in use, which is well suited to the requirements of economical manufacture, and` eapable of adjustment with comparative ease and expedition.

'Vith the above-noted and other objects in view, the invention Yconsists in certain novel features of construction andy combinations andai'rangements of parts, as will be more fully hereinafter described. s

The invention may bebetter understood from the followingdeseription in connec' tion with the accompanying drawings, wherein l Figure 1 is a View in front elevation of a my pulley embodying theinvention;

Fig. 2 is a view in side elevation of Fig. 1; Figs.` 3 and 4 are vertical sectional views through ythe pulley ltaken on the staggered lilies 3-3 and 4 4; respectively, 'ofFig 5;

Fig, ,5 is a longitudinal. sectional' view through the `pulley on approximately theline 5--5 of Fig. 3; v

Fig. 6 is a fragmentary sectional detail also on the line 5 5 of Fig. 3, but showing theposition of the parts when one pulley has been-contractedV and the other expanded; Fig. 7 is an inside face view of one of the heads;

Fig. 8 is a fragmentary sectional'detail on the line 8-8 of Fig. 5;

Fig. 9 isa'diagrammatic1view in side elevation showing the pulley in use between a driven shaft'and a drive shaft and the two pulley sections adjusted so that they are of they same diameter; y, Y A j Fig. 10 is a similar view but showing one section contracted and they other expanded to effect reduction ofthe speed of thedriven shaft; y

Fig. 11 is a top p'lanvi'ew of thediagram-- matrical showing of F ig.f 10.` j f l In Figs'. 1and'2 of the drawings I have used the reference character 10 to designate an overhead support of "any suitablenature from which depend a pair of bearing brack` ets lljournaling a; horizontal `shaft 12. Rigid with and depending from the shaft 12 are hangers 13 provided attheir lower ends lwith sectional bearings 11i` in'which ak shaft 15 is borne. l

It `is upon the shaft 15 that the pulley,

or, asa mattei' of fact, the two pulleys or ypulley sections designated generally by the numerals 16 and 17, are rotatable. As seen in Figs.V 9 to 11, one of the pulleys, such as 17, is'adapted tov be connected by a belt 18, toa pulley 19 on a driven shaft 20. The other pulley,',16,` is connected toa pulley 21 on a driving shaft 22,through the intermediacy of abelt23. The shaft 15 thus serves ineffect, as a countershaft carrying the variable Vspeed pulleys 16 and 17. The pulleys are so constructed that when the hangers 13 'are swungwith the supportingshaft 12 `from the position of Fig. 9 to the position of Fig. 10,:'the pulley '17y will be contracted by the pressure of its" belt 1S and pulley 16 'will be automatically expanded in a nan'ner to be' later'desc'ribed, to take uppthe slack in its belt 23. l

"Means l'are provided for rocking thejsliaft 12 vto effect swinging of lthe hangers 13 and t-he shaft 15 which they'carry. This means vhas been illustrated as a-worm gear k25fiXed is ai@ preparing snai-2a of are' shea 12,.

The gear meshes with a screw 26' on a shaft 2S journaled in bearings 27 integral with one if the brackets 11. Motion is imparted to the shaft 28 through a ysprocket chain 2t) running over a sprocket wheel 30 carried by the shaft 28. Obviously, rotation of the sprocket wheel acts through the screw and worm to swing the shaft 15 about the shaft 12 as a center. v

Each ofthe pulleys 16 and 17 is formed of a plurality of radially adjustable sections or segments 31 adapted to snugly intertit and form a closed drinn when they are fully contracted. .lhe outer heads of the drums are delined by disks keyed to `the shaft 15, as indicated at 33, and the drumshave a common inner head' defined by a spider keyed atto the shaft 15 and formed with a peripheral rimv 36. The rim 36 andthe edges of the disk 32 provide flanges which pre vent lateral slipping of the belts which run e over the pulley drums 1G and 17. Relative separation of the heads 32 is prevented by spacer sleeves 42 and tie bars 42a.

Each of the segments 31, as best seen in Figs. 1 and 8, is formed with laterally projecting lugs 39 working in guidegrooves 40 and 11 in its disk 32 and the spider 34 re spectively. Radial inward and outward movements of the segments '31 in a straight line is thus insured.

ln order that all of the segments of each drum may move simultaneously inwardly or v,outwar dly, I connect all of the segments through control links la to a central control disk 45 turning freely on the shaft 15. The control links 44 are disposed at angles to the radii of the drums so that pressure on any drum segment which tended to move the same inwardly in its guides 40, 4:1, would act through an associated link 44 to rotate disk 45 and draw all of the other segments inwardly by the action of their drag links. Means is provided whereby the contraction of one segmental pulley drum automatically effects the simultaneous expansion `of' the other segmental pulley drum. This means may conveniently comprise a series of rocker arms 5() fulcrumed iutern'iediate their ends on pins 51 carried by the spiders. The ends oi" the rocker arms project into the interiors of the drums and are connected directly to the segments by short pivot links 52. As best seen in Figs. 5 and 6, when one drum segment 31 of the drum 17 is forced inwardly, an associated rocker arm 50 is shifted from the position of Fig. 5 to the position of rig. 6, and a, corresponding segment 31 of the drum 16 is forced outwardly. The laterally alined segments of each drum are connected by rocker arms so thata maximum leverage is obtained to expand one drum as the other drum is, contracted. v

The operation of the device may best be followed fromthe diagram of Figs. 9 to 11.

nassaui ln Fig. 9 the drums are of equal size and it will be apparent that if the belts 23 and 18 are tightly stretched, movement of the shaft 15 to the left could not be accomplished without contraction of thc drum 17. Thus as the sprocket chain is operated to swing the hangers 13, the pressure of the belt 18 on the drum 17 acts through the intermediacy of the drag links and control disks to force all of the segments of this drum inwardly. It will also be evident that as the hangers 13 move from the position of Fig. 9 to the position of Fig. 1t), slack will be created in the belt 23. This slack is automatically taken care of, however, by the expansion of the pulley drum 16 as the drum 17 is contracted by the action of its belt.

From the foregoing description, it will be evident that a wide range of speed ratios may be obtained between the driving shaft 22 and the driven shaft 20 by the simpleexpedient of rocking the shaft 12 and swinging the hangers 13. Quite evident-ly the details of construction of the mechanism which efects'movement of the pulley drum segments, as well as the mechanism which is used to effect rocking of the shaft 12, might be considerably varied. In fact, numerous changes and alterations might be made in the construction of the device without departing from the spirit or scope of the appended claims.

lVhat is claimed is:

1. In combination a pair of segmental eX- panslble and contractible pulleys, means for pivotally supporting the same, an element rotatable with each pulley, and operative connections between said elements and pulleys whereby said elements are rotated relative to the pulleys in reverse directions to contract one pulley and expand the other simultaneously upon tensioning one of thek drive belts with which the pulleys are engaged.

2. In combination a laterally adjustable shaft, segmental expansible and contractible pulleys mounted. thereon, normally stationary discs loose on the shaft, operative connections between each disc and segments of one pulley whereby one disc is rotated to contract one pulley upon tensioning its belt and thereby rotates the other disc in a re verse direction toexpand the other pulley.

3. A variable speed pulley including a pair of segmental radially eXpansible and contractible pulley ydrums to be engaged by drive belts, a laterally movable shaft upon which the drums are mounted, discs loosely received on the shaft, normally tangentially disposed links connecting each disc and one of the segmental pulley drums, a collar loose on the shaft, and a plurality of levers pivotally mounted intermediate their ends and having their opposite ends pivotally connected with the segmental drums whereby upon lateral movement of the shaft a drive belt engaging one pulley Will be tensioned to contract the former pulley and expand the other.

4. In combination a laterally movable support, a pair of pulleys rotatable thereon in longitudinal alignment and each including a plurality of radially movable segments, an annulus loose on the shaft within cach set of segments, tangentially disposed links pivotally connected to each annulus rand corresponding segments, a plurality of links pivotally supported intermediate their ends within the pulleys and having their ends pivotally connected With adjacent segments, whereby upon contraction of one set'of segments incident to tensioning of a belt engaged therewith by lateral movement of the support the other set will be expanded.

5. A variable speed pulley including a pair of segmental radially expansible and contractible pulley drums adapted for the reception of belts from a drive shaft and a driven shaft, respectively, a carriage on which the drums are borne, means for shifting the position of the carriage relative to the shafts to which the belts are connected, means whereby a contraction of one drum caused by its Vbelt as an incident of such shifting, automatically effects expansion of the other drum to take up the slack in its belt,rcentral control disks housed Within each drum and freely rotatable on the drum shaft, and drag links disposed at an angle to the radii of the drums, connecting the segments and control disks.

ALBERT HORACE MIZE. 

